DNA Identifiers Loop Back to Producers

Suzanne Deutsch

Thu, 2012-03-15 13:34

As pork producers continue to use antibiotics strategically, this tool offers some options.

DNA testing has come a long way. Fans of the CSI television franchise tune in every week to see how forensic scientists use tiny tissue samples to unveil the culprit of a crime. DNA traceability could also be a valuable tool in tracing food back to its origins when needed.

Researchers from the Canadian Swine Health Board, the University of Prince Edward Island (UPEI), and the Atlantic Veterinary College (AVC) are betting the technology can offer benefits to pork producers, too.

In the first phase of a research project, they analyzed DNA as a tool to breed healthier, better-performing hogs. DNA technology also shows great potential for unraveling the mysteries surrounding on-farm mortalities or disease outbreaks by providing an effective and rapid feedback loop for farmers.

Lost Identity

Unless a producer is in the seedstock business, where every pig is given a unique identification, it is unlikely that a pig can be traced back to its birth parents, explains Daniel Hurnik, DVM, UPEI’s industry chair for swine research and associate professor at the Atlantic Veterinary College.

“Pigs in weaner rooms or finishing barns all look the same and do not have unique identifiers,” Hurnik notes. “If a pig has a genetic defect or a health problem, there is no way to prove it was caused by genetics or parentage.”

That may change soon, as researchers successfully identified hogs’ parentage by using IdentiGEN, Canada’s DNA TraceBack system. If a sire’s offspring consistently have problems, he can be crossed off the list of sires used in a commercial breeding program.

“We’re not talking about the ability to influence the genetics of one individual, but rather the productivity of an entire herd by identifying the genetic cause of problems faster than it’s been done in the past,” he explains.

All health issues cannot be blamed on genetics, nor can the use of genetics guarantee optimal health. However, disease susceptibility has a genetic basis, Hurnik points out, and that is why the second part of their study will focus on how this can be factored into genetic selection.

Researchers will track genetically linked conditions like birth defects, hernias and retained testicles to determine if a genetic line is more prone to these problems. A parallel benefit is the ability to select sires that produce faster-growing, leaner offspring or other attributes they are interested in, he notes.

The biggest hurdle with genetic analysis is accuracy, since researchers tend to work with probabilities and not absolutes. While the current cost might put it beyond the reach of most producers, Hurnik expects DNA analysis will become more affordable with time.

“My goal as a veterinarian is to try and develop tools to reduce the prevalence of disease and help farmers be more competitive. This is one of many ways to do that,” he assures.